Please help..recovering corrupt/incomplete Huffyuv file?

[John D.]

Hi,

I've got a project which I rendered out from my NLE using Huffyuv. The video is about an hour long. I set it up using the 'best' setting in Huffyuv, minus the "always suggest RGB output" option (I de-checked that to avoid any possible colorspace conversion snafu when I encode it using CCE).

After 27 hours of rendering, the damn thing crashed with 5% left to go. So I rebooted and checked my HDD and the file is there...file size approx. 35.5 gig...but obviously not complete since the render crashed before it finished.

Here's the problem. The file won't open. WMP gives me no picture and a high pitched scrambled whining noise. My NLE won't import it. Virtualdub won't open it, it says "cannot detect file type". CCE won't accept the file, it says it's not an .avi file. I've tried AVI Fix Repair Joiner, Divfix, Avifix, AVIMaster (Can't get the hang of that one, CMD has never been my forte)
and some other prog that used a Panda as a logo, I forget. The problem with all of them is that none of them seem to recognize it as an .avi file. Avifix tells me the file is less than 5kb in size (!!!) and won't even go as far as trying to open it.

My guess is there is corrupt or missing information in the file header but I have no idea how to fix it or what to use.

If I have to re-render this file I'm going to go nuts. I grant you, 27 hours isn't all that long to wait but I've got other stuff I need to work on and I can't keep locking up the PC...so how do I recover/edit/fix this file? Any sugggestions would be most appreciated.

[guns1inger]

Try VLC (VideoLan Client). It seems to be able to play anything, including parts of incomplete downloads. You might be able to salvage some of it.

[mpack]

The last thing that gets done before the AVI file closes would typically be that the last index chunk is written (a file that size must be OpenDML, so will have several index chunks), and then the header will be patched with finalised data - total number of frames, index of indexes and so on. File space will have been allocated for the header as the file was being written, but since this was never finalized the stub header could be partly or completely junk. What does Windows "properties" say about the file?

Plus of course the software crashed with the file still open, so there's no way around the fact that data near the end of the file will have been lost.

The file should still be RIFF comformant, so it should be readable as a generic RIFF up to the corruption at the end (eg. "RiffWalk" should show the contents), but no media player will accept it because of the duff header and missing index... If it were me I would write a little program to parse the frames, recreating the indices and patching the header with what I know to be the correct info, but I doubt you would find a ready made tool that can fix errors this serious (I vaguely recall seeing a tool on this site for patching AVI headers - but I wouldn't get my hopes up).

[John D.]

Hmm. Windows properties shows only that it's a video file...under "advanced" all it says is "summary properties are unavailable for the selected source".

When I ran the file through GSpot it also came back as saying "not a valid avi file" although hitting "render" showed that it could detect the audio stream ok, which seems kind of odd.

Oh and I also gave it a shot with VideoLAN...nothing happens.

If I could get the file into a readable condition I can always re-render out the lost bit at the end as another file and then edit the two .avi's together later...

I gather there's no readily available app to assist in writing a prog like the one you suggested? It's not something I can do in, say, Avisynth, is it?

[mpack]

I gather there's no readily available app to assist in writing a prog like the one you suggested? It's not something I can do in, say, Avisynth, is it?

I'm afraid not. AVIsynth accepts AVI files, and the executive summary of your problem is that you don't have an AVI file, you have a file which is probably recognisable as RIFF, but lacks some or all of the header info that makes it a usable AVI. A program to recover the data would be a one off... I can't imagine a generic tool that could do the job... ok, a hex file editor could technically do it I suppose, but no-one in their right mind would try that on something this complex.

[John D.]

Ok...so here's what I'm wondering. If there was a way to copy the header from another file which was rendered in the exact same format and attach it to the corrupt file (is there a way???) , would that at least give me a shot at being able to open the file in some .avi repair prog and have it fix whatever errors there were? (obviously if I was able to put a new header on the file the length would be wrong, etc. etc. but perhaps one of the tools I mentioned earlier could fix that as long as there was a valid header which described what kind of file it was).

It seems that the number one problem I"m having trying to open the file in ANY app. is that it's not identifying itself as an .avi...

[mpack]

Copying the header from another file is a tempting proposition... but I don't know if it would work... The fixed part of the header would be fine, so the file would be recogisable as an AVI. The number of frames would most likely be wrong, and the superindex which you copy over would point to the wrong locations in the file for the sub-indexes.

But... I don't know what kind of errors one of those "avi fix" apps will tolerate. You want something that will recognise it as an AVI, then walk the riff chunk list building an index as it goes... and it has to recognise and support the OpenDML format for AVIs greater than 4gigs... and NOT crash when it hits the corruption at the end.

[John D.]

Yeah, I was wondering about the corruption at the end of the file and what that would do to a 'repair' prog.

So what would I use to copy the file header from another file? A binary text editor, then?

[mpack]

So what would I use to copy the file header from another file? A binary text editor, then?

I don't know of a ready made app that would make this easy. Do you know any programmers? It would be trivial to write a little console app to do this.

One thing is that I'm worried that you'll just damage the file further, so take care. If you have plenty of disk space then perhaps make a backup copy first.

Also, if you could get hold of a copy of the old RiffWalk application (or even better: an more uptodate equivalent) then it should be very informative to run this on your damaged file. This tool will list all the riff chunks (redirect the output to a text file), and that will tell you whether the correct header chunks are present at all, and what size they are (ie. if you do find a copy app, this tells you how many bytes to copy).

I suspect that your most practical option is to reencode, and hope your unnamed NLE tool doesn't crash again...

[sacajaweeda]

https://www.videohelp.com/tools?tool=ASF-AVI-RM-WMV_Repair

Give that one a try. I've used it a couple of times to recover AVI files. Works like a champ.

Feed it your bad file and it will ask you for a clip of material captured/created with the same settings to reference the info it needs to repair the bad header info in your file.

I will add that it is a very lengthy process. It was for me anyways. I was using it to recover some capture files of football games. 3+ hour long AVI file and the power flickers near the end and my computer reboots. No programs could open or play the 20GB AVI file, but this program fixed it. Several hours for the process though. Just fire it off and go find something else to do for a while, or just to bed, because it's gonna be a while.